岸线码头密度对河道水动力和污染物输移影响分析——以武汉河段为例

为研究岸线码头密度对河流水动力变化及污染物输移的影响,以武汉河段为例,基于Mike21模型建立了适用于该河段的平面二维水动力-水质模型,计算了长为9.6 km的岸线范围内布置不同密度码头群后引起的附近区域内水位、流速变化以及突发水污染事故后的自净能力变化,从空间差异性、最大变幅等角度对比了三者的差异,并归纳了码头密度与水动力条件、污染物浓度变幅之间的关系.结果 表明:(1)随着码头密度增加,工程区上游水位变化较流速更敏感,工程区及下游局部位置水位变幅较小,而流速变化较为敏感,表现为前沿主流区流速增大,近岸区流速减小;当码头密度大于1.25～2.5座/km的临界范围后,水动力条件随码头密度的变幅逐渐减缓.(2)修建码头后,受水动力变化影响,工程区河段上游污染物浓度变化呈"峰前减、峰后增",但工程区下游呈"峰前增、峰后减"的特征;工程区间内表现为主流区浓度增大、近岸带浓度减小、高浓度滞留时间总体增加的变化特点.(3)受码头工程群影响,无论是区间整体上,还是局部范围内,污染物浓度相对水动力条件变幅更大,对河段内水源地的取水可能造成不利影响.以上认识对于河流岸线开发利用规模选取和效应评估具有参考意义.     

Concentrations and accumulation rates of polychlorinated biphenyls in soil along an urban–rural gradient in Shanghai

Environmental Science and Pollution Research - This study proposed an in situ soil experimental system to quantify concentration and accumulation rates of polychlorinated biphenyl (PCB) congeners...     

Compartmentation and effects of lead (Pb) in the collembolan,Folsomia candida

Environmental Science and Pollution Research - The impact of soil lead (Pb) pollution on survival, growth, and reproduction of the collembolan, Folsomia candida, and Pb compartmentation in its gut...     

Evaluating provincial eco-efficiency in China: an improved network data envelopment analysis model with undesirable output

Environmental Science and Pollution Research - In this study, an improved matrix-type network data envelopment analysis (NDEA) model with undesirable output was developed to evaluate the...     

Functional wastepaper-montmorillonite composite aerogel for Cd2+ adsorption

Environmental Science and Pollution Research - In this study, a composite aerogel (WP-MMT) composed of wastepaper (WP) and montmorillonite (MMT) was prepared by ambient pressure drying technology...     

N2O profiles in the enhanced CANON process via long-term N2H4 addition: minimized N2O production and the influence of exogenous N2H4 on N2O sources

Environmental Science and Pollution Research - Production of the greenhouse gas nitrous oxide (N2O) from the completely autotrophic nitrogen removal over nitrite (CANON) process is of growing...     

Soil labile and recalcitrant carbon and nitrogen dynamics in relation to functional vegetation groups along precipitation gradients in secondary grasslands of South China

Environmental Science and Pollution Research - Soil labile and recalcitrant carbon (C) and nitrogen (N) are strongly controlled by plant inputs and climatic conditions. However, the interrelation...     

CO2资源化利用的现状及前景

介绍了CO2分离捕集最新工艺——电化学法、膜法、化学循环燃烧法的研究进展。评述分析了CO2的各种资源化应用前景：CO2气体用作生物碳源、辅助注射成型剂及有机物（如氨基甲酸酯、表面活性剂）合成原料等;液态CO2用于人造金刚石、热泵干燥、超临界CO2萃取及固体干冰冷喷射清洗等。CO2作为一种潜在的丰富碳源,应不断研发其新的应用领域,加快其工业化应用。     

土壤渗滤处理系统运行控制的模拟研究

通过建立地下水数学模型,回答了土壤渗滤工程运行控制中的两个难点问题:(1)工程运行水力负荷.当工程地块周边存在河流时,河流水位低时,有助于增加水力负荷,反之则降低水力负荷;实际土壤运行面积的增加和独立运行单元之间的间距增加也能够增加工程运行水力负荷.(2)地下水水质监测井的优化布设.模拟工程运行后地下水水质空间分布特征,在地下水水质最不利的位置和其他特别关注的位置布置监测井,从而能够以具有典型代表性且数目较少的监测井达到准确评估工程对地下水水质影响的目的.     

流化催化裂化烟气脱硫助剂的制备及其脱硫活性

采用溶胶-凝胶法制备锌铝助剂,该助剂于700℃焙烧后与流化催化裂化（FCC）催化剂进行机械混合,制得混合催化剂;在FCC烟气工业模拟装置上考察混合催化剂的脱硫活性,用混合催化剂的脱硫活性来反映锌铝助剂的脱硫性能。实验结果表明,氧化锌质量分数为10％的锌铝助剂的脱硫活性最佳,脱硫率达62．5％。采用红外光谱和X射线衍射（XRD）对锌铝助剂的脱硫机理进行了研究,红外分析结果表明,弱的L酸中心有利于锌铝助剂脱硫,XRD分析结果表明,锌铝助剂在锌铝尖晶石结构尚未完全形成时,存在较多的晶格缺陷,能够有效地吸附烟气中的SOx,将其转化为H2S。